The existence of an Adjustable FinderBracket for 50mm guidescope?

[pompeydano]

Hi all,

Wouldn't it be good if there was an adjustable finderscope bracket that would house a 50mm mini guidescope (like the Orion one), that had adjustable screws, a dovetail attachment and enough space so that the guidescope could be independantly moved around the sky enough lock onto a guide star (via synguider), whilst keep the main image centred on the main scope?

Does anyone know if such a thing exists?  It would be hugely useful in keeping the weight down (rather than the ST80 and skywatcher guidescope mount) and guiding at the same time.

I've found some possibilities on FLO,

the williams optics finder bracket.

or

Baader MQR-IV Finder Holder for 60mm finderscopes.  (which i'm not sure that the screws would hold a 50mm scope in place - the smaller 50mm version might not have enough gap)

or

stellavue R50D

anybody tried this method of autoguiding?  Anybody got any suggestions?

Thanks

Dan

[jnc71106]

i think it very unlikely you would ever need to use an adjustable bracket if using a finderguider setup as your FOV is very large. I have used an ST80 and QHY5 before and not once did i ever fail to find a star and now for the last year i have used a finderscope in the supplied bracket with my QHY5 and again not once has there not been a guide star on screen in fact my finderscope is fixed in place so as not to have any flexture in my setup

have you been struggling to find guide stars ???

[DrRobin]

Hi Dan,

I use a Skywatcher 50mm finder with the eyepiece removed and a home made adapter that goes to a standard 1.25" fitting, in to which I put a QHY5.  It never fails to find a guide star and I use the finder adjuster screws to centre the finder to the scope, it helps when using a scope with very narrow FoV.  My 50mm finder has a focal length of around 225mm, so a QHY5 gives about 120 x 90 arc minutes.  This nearly matches the FoV of my 8" newt with 800mm focal length and a Canon 600D.

I know you can buy adapters from Modern Astronomy, among others.

Robin

[pompeydano]

Thanks Jake,

I had a try of M31 the other day with a canon 1100D on an Evostar 90.  admitadely, the light pollution in portsmouth wasn't helping, but whilst the image of andromeda was nicely central in the frame, any useful guidestars were outside the centre FOV of the mini guidescope, even with a bit of a wiggle.  For the synscan, I have to either adjust the mount to the get the star in the centre (which doesn't help the main image) or faff around with the two thumscrews that come with the standard bracket.  In short...a pain.

Normally when I use a ST80 on a skywatcher guidescope mount, (with my larger 200pds) it's easy as pie, but the weight of my kit is getting near the top end, so I thought about this mini version instead to keep the weight down.  I have some more kit planned (CCD) so i'm guessing that might increase the weight more.

also, i had a little focusing trouble with the synguider as the focal point seemed to be on the absolute limit of the eyepiece attachement...so it did wobble around a bit (eyepeice tube extension in post!!).

I plan on having another go tonight on something else, so maybe it might be just the way (and where) i'm doing it....badly!

Dan

[pompeydano]

robin

I did wonder that.... I had a try twisting the end off, but it's on there good and tight.  I had visions of bits of finderscope flying through the air as I tried to get the end off!

ta

Dan